package demo09_集合类;

import java.util.List;
import java.util.UUID;
import java.util.concurrent.CopyOnWriteArrayList;

public class TestArrayListB {

    public static void main(String[] args) {
        List<String> list = new CopyOnWriteArrayList<>();
        for (int i = 0; i < 100; i++) {
            new Thread(() -> {
                list.add(UUID.randomUUID().toString().substring(0, 4));
                System.out.println(list);
            }, String.valueOf(i)).start();
        }
    }
}
